From f2391d99d5487379963f032e2bf46f93494bb5cc Mon Sep 17 00:00:00 2001
From: Bill Zissimopoulos <billziss@navimatics.com>
Date: Sun, 2 Apr 2017 22:40:43 -0700
Subject: [PATCH] src: dotnet: WIP

---
 src/dotnet/FileSystem.cs | 14 ++++++++------
 src/dotnet/Interop.cs    | 27 +++++++++++++++++++++++++++
 2 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/src/dotnet/FileSystem.cs b/src/dotnet/FileSystem.cs
index ef844747..718cf432 100644
--- a/src/dotnet/FileSystem.cs
+++ b/src/dotnet/FileSystem.cs
@@ -36,13 +36,16 @@ namespace Fsp
         }
         public void Dispose()
         {
-            Dispose(true);
+            lock (this)
+                Dispose(true);
             GC.SuppressFinalize(true);
         }
-        protected void Dispose(bool disposing)
+        protected virtual void Dispose(bool disposing)
         {
             if (IntPtr.Zero != _FileSystem)
             {
+                Api.FspFileSystemStopDispatcher(_FileSystem);
+                Api.FspFileSystemSetUserContext(_FileSystem, null);
                 Api.FspFileSystemDelete(_FileSystem);
                 _FileSystem = IntPtr.Zero;
             }
@@ -136,8 +139,8 @@ namespace Fsp
                 ref _VolumeParams, ref _FileSystemInterface, out _FileSystem);
             if (0 <= Result)
             {
+                Api.FspFileSystemSetUserContext(_FileSystem, this);
 #if false
-                _FileSystem->UserContext = this;
                 FspFileSystemSetOperationGuardStrategy(_FileSystem, Synchronized ?
                     FSP_FILE_SYSTEM_OPERATION_GUARD_STRATEGY_COARSE :
                     FSP_FILE_SYSTEM_OPERATION_GUARD_STRATEGY_FINE);
@@ -150,6 +153,7 @@ namespace Fsp
             }
             if (0 > Result && IntPtr.Zero != _FileSystem)
             {
+                Api.FspFileSystemSetUserContext(_FileSystem, null);
                 Api.FspFileSystemDelete(_FileSystem);
                 _FileSystem = IntPtr.Zero;
             }
@@ -157,9 +161,7 @@ namespace Fsp
         }
         public void Unmount()
         {
-            Api.FspFileSystemStopDispatcher(_FileSystem);
-            Api.FspFileSystemDelete(_FileSystem);
-            _FileSystem = IntPtr.Zero;
+            Dispose();
         }
 #if false
         PWSTR MountPoint()
diff --git a/src/dotnet/Interop.cs b/src/dotnet/Interop.cs
index ad6a9f1b..4e21c9f5 100644
--- a/src/dotnet/Interop.cs
+++ b/src/dotnet/Interop.cs
@@ -16,6 +16,7 @@
  */
 
 using System;
+using System.Diagnostics;
 using System.Security.AccessControl;
 using System.Runtime.InteropServices;
 using System.Security;
@@ -409,6 +410,32 @@ namespace Fsp.Interop
             else
                 return FspFileSystemSetMountPointEx(FileSystem, MountPoint, IntPtr.Zero);
         }
+        internal unsafe static Object FspFileSystemGetUserContext(
+            IntPtr FileSystem)
+        {
+            IntPtr UserContext = Marshal.ReadIntPtr(FileSystem, sizeof(IntPtr));
+            return IntPtr.Zero != UserContext ? ((GCHandle)UserContext).Target : null;
+        }
+        internal unsafe static void FspFileSystemSetUserContext(
+            IntPtr FileSystem,
+            Object Obj)
+        {
+            if (null != Obj)
+            {
+                Debug.Assert(IntPtr.Zero == Marshal.ReadIntPtr(FileSystem, sizeof(IntPtr)));
+                GCHandle Handle = GCHandle.Alloc(Obj, GCHandleType.Weak);
+                Marshal.WriteIntPtr(FileSystem, sizeof(IntPtr), (IntPtr)Handle);
+            }
+            else
+            {
+                IntPtr UserContext = Marshal.ReadIntPtr(FileSystem, sizeof(IntPtr));
+                if (IntPtr.Zero != UserContext)
+                {
+                    ((GCHandle)UserContext).Free();
+                    Marshal.WriteIntPtr(FileSystem, sizeof(IntPtr), IntPtr.Zero);
+                }
+            }
+        }
 
         /* initialization */
         [DllImport("kernel32.dll", CallingConvention = CallingConvention.StdCall, SetLastError = true)]